Miro

Where do you have the game from? Are you using any mods? Are you playing with the original DVD in your Drive? Have you tried un-installing and re-installing the game? What about removing the gta3.set file located in the GTA3 User Files folder?

Make sure you have the Trails OFF, VSync ON & Frame Limiter ON (or OFF, depends here). All these can be set in the Menu -> Options -> Display Setup. Good luck.